SMG no start but pump primes

[Krazi3azn]

Hi there,
Have a e46 m3 that won't start and the smg keeps priming when key is in ignition. It doesn't even try cranking and the shifter won't move. Currently it can be rolled so I assume it's in neutral.

Haven't dived too deep into it yet but inpa shows error code s0012 "no communication possible with: transmission control unit".

[eacmen]

Make sure brake pedal switch is working.

[Darbshaw]

It’s been so long since I’ve had my car running that I haven’t had to mess with any SMG issues.

I would use inpa to check and see if your brake switch is currently active as said before (sorry I can’t see your post because mobile issues)
My second guess would be that your clutch slave is bad. This should be diagnosable through one of the smg screens on inpa to see if it’s activating or not.

Again wish I could be more direct with instructions, my cars been out of commission getting rebuilt.


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[Petener]

Hi there,
Have a e46 m3 that won't start and the smg keeps priming when key is in ignition. It doesn't even try cranking and the shifter won't move. Currently it can be rolled so I assume it's in neutral.

Haven't dived too deep into it yet but inpa shows error code s0012 "no communication possible with: transmission control unit".

Try this.. Push starting an SMG "automatic" BMW M3 e46 - YouTube

[Arith2]

Check for water or damage to your SMG control unit and the harness. See if anything cut a wire. The connector could've slipped out of the bracket and was never put back in previously. This is a communication issue with the unit so I don't know why a brake switch wouldn't throw a CAN fault. The brake switch isn't on a CAN line unless BMW does it weird. Still worth checking anyways. I would say something isn't talking to the SMG tell it to go. Possibly a DME issue. Can you see any PIDs in the TCM through INPA or can you even connect?

[M3Pat]

Check for water or damage to your SMG control unit and the harness. See if anything cut a wire. The connector could've slipped out of the bracket and was never put back in previously. This is a communication issue with the unit so I don't know why a brake switch wouldn't throw a CAN fault. The brake switch isn't on a CAN line unless BMW does it weird. Still worth checking anyways. I would say something isn't talking to the SMG tell it to go. Possibly a DME issue. Can you see any PIDs in the TCM through INPA or can you even connect?

Actually the brake switch is on can.

[Arith2]

Actually the brake switch is on can.

Of course it would be. BMW: 1 Me: 0

[sapote]

Try this.. Push starting an SMG "automatic" BMW M3 e46 - YouTube

This helps in case the starter is bad. But the OP could not move the shifter which means he cannot engage the gears (no hydraulic pressure I think). Worst, if it engaged in gear then pushed and started running, but no hydraulic pressure and so it cannot disengage the gear when you wish to stop!

[Rich022]

Sometimes I’ve had to press down on the brake peddle extra hard.

[sapote]

Sometimes I’ve had to press down on the brake peddle extra hard.

Maybe need to check the brake switch triggering distance.

[Irhase46m3]

Hi There - I had a similar issue, except that the pump wouldn't constantly be running, it would prime just fine but it wouldn't engage gear and I had "no communication" sporadic error - The pump harness was loose, the twist lock connector that is. Hope this helps!

[eacmen]

I love how OP cross posts the same message on 4 different forums asking for help then goes dark. Cmon OP, we’re trying to help you here.